The GeoBase Orthoimages 2005-2010 are Spot 4 and Spot 5 raster data and comprise five spectral bands: one panchromatic band with a pixel size of 10 m, and four multispectral bands with a pixel size of 20 m. The orthoimages are produced in accordance with the 1983 North American Reference System (NAD83SCRS) using the Universal Transverse Mercator (UTM) and Lambert Conformal Conic (LCC) projections. Each GeoBase Orthoimage 2005-2010 covers an area of approximately 3 600 km2, or 60 km x 60 km of the Earth's surface. All orthoimages are created with the most accurate control data available at the time. Various sources of planimetric data are used to rectify the images, and priority is given to the most accurate...
The orthoimage data set is a complete set of cloud-free (less than 10%) orthoimages covering the Canadian landmass and created with the most accurate control data available at the time of creation. The imagery has been corrected with either provincial and aerial triangulation data or, if not available, the most accurate NTDB data. The objective is to obtain accuracy of 30 metres or better in the South and 50 metres or better in the North for a 90% level of confidence. The accuracy is evaluated for each orthoimage data set. The control data, which has been extracted from sources as mentioned above, can consist of road intersection vector data or lake/island centroids. In some cases the intersection of the centre...
